Asynchronous multi-purpose battery interface

ABSTRACT

A method and apparatus for controlling a battery operating mode. The method includes connecting an electronic processor to a first electrical contact of a battery interface via a switch; generating, with the electronic processor, an initialization pulse for a signal demultiplexer of a battery; transmitting the initialization pulse to the signal demultiplexer; generating, with the electronic processor, a data word indicating a desired operating mode; transmitting the data word to the signal demultiplexer; generating, with the signal demultiplexer, a signal to electrically connect a first battery switch to the first electrical contact, the first battery switch selected based on the data word; receiving, with an analog to digital converter of the electrical device, a signal indicating the operating mode voltage; and verifying, with the electronic processor, a correct operating mode based on the operating mode voltage.

BACKGROUND OF THE INVENTION

Portable electrical devices often include removable batteries or batterymodules that are connected to an electrical device through a number ofelectrical contacts in a battery interface. To manage an electricaldevice's size and cost, the number of electrical contacts connecting thedevice and a removable battery should be limited. At the same time, itis desirable to have or add functionality, such as battery monitoringand communication functionality, to a battery interface. However,battery monitoring, communication, and other functionality generallyincreases the number of electrical contacts in a battery interface.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

The accompanying figures, where like reference numerals refer toidentical or functionally similar elements throughout the separateviews, together with the detailed description below, are incorporated inand form part of the specification, and serve to further illustrateembodiments of concepts that include the claimed invention, and explainvarious principles and advantages of those embodiments.

FIG. 1 is a block diagram illustrating an apparatus for controlling abattery operating mode in accordance with some embodiments.

FIG. 2 is a schematic of a window comparator circuit in accordance withsome embodiments.

FIG. 3 is a flowchart of a method of controlling a battery operatingmode in accordance with some embodiments.

Skilled artisans will appreciate that elements in the figures areillustrated for simplicity and clarity and have not necessarily beendrawn to scale. For example, the dimensions of some of the elements inthe figures may be exaggerated relative to other elements to help toimprove understanding of embodiments of the present invention.

The apparatus and method components have been represented whereappropriate by conventional symbols in the drawings, showing only thosespecific details that are pertinent to understanding the embodiments soas not to obscure the disclosure with details that will be readilyapparent to those of ordinary skill in the art having the benefit of thedescription herein.

DETAILED DESCRIPTION OF THE INVENTION

Embodiments described and illustrated are directed to, among otherthings, an apparatus for controlling a battery operating mode. In oneexample, the apparatus includes an electrical device that includes aplurality of switches and an electronic processor. The electronicprocessor is configured to generate an initialization pulse, generate anasynchronous data word indicating a desired operating mode, receive anoperating mode voltage, and verify a correct operating mode based on theoperating mode voltage. The apparatus also includes a battery interface.The battery interface includes a first electrical contact. A first oneof the plurality of switches electrically connects the electronicprocessor to the first electrical contact. The apparatus also includes abattery. The battery includes a plurality of battery switches and asignal demultiplexer electrically connected to the first electricalcontact. The signal demultiplexer is configured to receive theinitialization pulse, receive the data word, and generate a signal toelectrically connect a first battery switch of the plurality of batteryswitches to the first electrical contact. The first battery switch isselected based on the data word, and an operating mode voltage istransmitted from the first battery switch to the electronic processorvia the first electrical contact. The electronic processor uses ananalog-to-digital converter to verify that the battery is operating inthe correct operating mode based upon the received operating mode.

FIG. 1 illustrates an apparatus 100 for controlling a battery operatingmode according to one embodiment. In the example provided, the apparatus100 includes an electrical device 105. The electrical device 105 may be,for example, a handheld communication device, a portable two-way radio,or other portable electrical device that utilizes a rechargeable,replaceable, or modular battery.

The electrical device 105 includes an electronic processor 110, a firstswitch 113, a second switch 114, and a third switch 115, which aresometimes referred to as a plurality of switches 113-115, and ananalog-to-digital converter (“ADC”) 120, which in some embodiments maybe replaced by an analog comparator. The electronic processor 110 isconfigured to control the electrical device 105, the actuation of theplurality of switches 113-115, and the ADC 120. It is to be understoodthat the plurality of switches 113-115 may include only two switches ormay include more than the three illustrated switches.

A battery 125 is connected via a first electrical contact 127 of abattery interface 130 to the electronic processor 110 via the firstswitch 113. The electronic processor 110 is also configured to generatean initialization pulse and a data word indicating a desired operatingmode for the battery 125.

The desired operating mode may be an I2C operating mode, a near-fieldcommunication operating mode, a battery cell voltage monitoringoperating mode, a one-wire operating mode, or another suitable operatingmode. In the I2C mode, the components in the battery 125 communicatewith the electronic processor 110 using the inter-integrated circuitprotocol. The I2C mode is used to communicate with a co-processor of thebattery 125 to handle battery functions such as wireless charging or asa communication protocol. In the near-field communication operatingmode, the battery 125 includes an antenna that is used by a near-fieldcommunication transmitter/receiver in the electrical device 105 tocommunicate with external devices. In the battery cell voltagemonitoring operating mode, real-time voltage measurements of batterycells are obtained in situations where this data normally would not beavailable, such as in a situation where the battery 125 is apower-supply battery (for example, a battery where battery cells feed adirect current (“DC”) regulator so that a fixed voltage is applied tothe electrical device 105 from the battery 125). In the one-wireoperating mode, the battery 125 allows the electrical device 105 tocommunicate with various other devices within the battery 125, such as afuel gauge integrated circuit or an electrically erasable programmableread-only memory (“EEPROM”) integrated circuit storing various batteryparameters.

The initialization pulse is generated by the electronic processor 110using the first switch 113 and a pull-down resistor 126. In mostinstances, the initialization pulse is a low-voltage signal with a pulsewidth that is greater than a pulse width of a reset pulse for a currentoperating mode of the battery 125. The initialization pulse is generatedby switching the first switch 113 to the pull-down resistor 126 for thedesired pulse width of the initialization pulse and then switching thefirst switch 113 to connect to the electronic processor 110. Theinitialization pulse indicates to the battery 125 that a new desiredoperating mode will be transmitted from the electronic processor 110 andis also used to differentiate between multiple communications protocolson the same first electrical contact 127. The initialization pulse alsoprovides an indication to the battery 125 to wait to receive the desiredoperating mode as the data word.

In one example, the data word is generated as an n-bit serial word byswitching the first switch 113 in between the pull-down resistor 126 andthe electronic processor 110 to generate a sequence of high and lowvoltages (binary 1 and 0 values) that is then transmitted to the battery125. The data word indicates the desired operating mode to the battery125. In some embodiments, the data word is generated by the electronicprocessor 110 asynchronously from the operation of the electrical device105.

The battery 125 includes a first battery switch 133, a second batteryswitch 134, and a third battery switch 135, which may be described as aplurality of battery switches 133-135, a signal demultiplexer 140, apull-up resistor 142, a battery current sensing circuit 145, batterycells 146, and a one-wire device 147. The first battery switch 133 ofthe plurality of battery switches 133-135 selectively connects theelectronic processor 110 via the first electrical contact 127 to thebattery current sensing circuit 145, the pull-up resistor 142, or theone-wire device 147 of the battery 125 based upon a control signal fromthe signal demultiplexer 140, as is described in greater detail below.The signal demultiplexer 140 is also configured to control actuation ofthe plurality of battery switches 133-135 by generating control signalsfor each battery switch of the plurality of battery switches 133-135. Itis to be understood that the plurality of battery switches 133-135 mayinclude only two switches or may include more than the three illustratedswitches. In one embodiment, at least one of the plurality of batteryswitches 133-135 is an XOR switch.

The battery current sensing circuit 145 detects current drawn from thebattery cells 146 so that the signal demultiplexer 140 can determine ifthe electrical device 105 is in an active state (e.g., drawing currentfrom the battery cells 146). The battery current sensing circuit 145 canalso be used by the signal demultiplexer 140 to detect the removal ofthe battery 125 from the electrical device 105. When the battery 125 isremoved, the signal demultiplexer 140 generates a signal to shut downvarious battery attachments (described below) and also power up in aknown state when next attached to the electrical device 105 or anotherelectrical device. The one-wire device 147 is an integrated circuitwithin the battery 125 performing various functions for the battery 125,such as a fuel gauge integrated circuit or an EEPROM containing variousparameters for the battery 125.

In one example, the signal demultiplexer 140 includes a windowcomparator circuit 150. The window comparator circuit 150 monitorssignals from the electronic processor 110 to determine if theinitialization pulse is received. When the initialization pulse isreceived, the signal multiplexer 140 enables the pull-up resistor 142and the window comparator circuit 150 then waits for the data wordsignal and provides the data word to the signal demultiplexer 140.

A schematic of the window comparator circuit 150 is illustrated in FIG.2. In the example illustrated, the window comparator circuit 150includes a logic-high op-amp 205, a logic-low op-amp 210, shiftregisters 215, pulse width counter 220, and an enable shift registerscircuit 225.

In one example, the window comparator circuit 150 receives a signal 230via the first battery switch 133. The signal 230 is provided to both thelogic-high op-amp 205 and the logic-low op-amp 210.

The logic-high op-amp 205 receives the signal 230 as the inverting inputvoltage and receives VCC—0.5V as the non-inverting input. The resultingoutput voltage of the logic-high op-amp 205 is high if the signal 230 isa high-voltage signal and low if the signal 230 is a low-voltage signal.

The logic-low op-amp 210 also receives the signal 230 as the invertinginput voltage and receives 0.5 V as the non-inverting input. Theresulting output voltage of the logic-low op-amp 210 is low if thesignal 230 is a high-voltage signal and high if the signal 230 is alow-voltage signal.

When the initialization pulse, which is a low-voltage signal, isreceived by the window comparator circuit 150, the logic-high op-amp 205outputs a low voltage to the shift registers 215. The logic-low op-amp210 outputs a high voltage to the pulse width counter 220, which countsthe duration of the high output voltage from the logic-low op-amp 210.If the duration of the high output voltage is greater than a presetvalue of a pulse width for the initialization pulse, the pulse widthcounter 220 outputs a signal to the enable shift registers circuit 225.In response to receiving the signal from the pulse width counter 220,the enable shift registers circuit 225 sends a signal to the shiftregisters 215 to enable the shift registers 215, which allows the shiftregisters 215 to receive the data word.

After the shift registers 215 are enabled, the data word is received asthe signal 230. The logic-high op-amp 205 provides a signal setting waveform to the shift registers 215. The signal setting wave form representsthe data word to be stored in the shift registers 215. Based on the dataword stored in the shift registers 215, the signal demultiplexer 140controls the plurality of battery switches 133-135. For example, if thedata word indicates that the battery 125 should be operated in a cellvoltage monitoring mode, the signal demultiplexer 140 generates a signalto connect the first battery switch 133 to the battery current sensingcircuit 145.

A hardware counter may also provide a counter for a maximum amount oftime to receive the data word from electronic processor 110. If themaximum amount of time elapses, the window comparator circuit 150 maystop receiving the signal 230 and operate as if the full data word isreceived. The maximum amount of time may be dynamically set or apredetermined value.

Returning to FIG. 1, the signal demultiplexer 140 controls the firstbattery switch 133 to connect the battery current sensing circuit 145 orthe one-wire device 147 to the first electrical contact 127 of thebattery interface 130 based on the data word.

In some embodiments, the battery interface 130 includes a plurality ofelectrical contacts 155-156. In some embodiments, the data word storedin the shift registers 220 of the window comparator circuit 150indicates which of the plurality of battery switches 133-135, such asthe second battery switch 134 and the third battery switch 135, shouldbe connected to respective electrical contacts 155-156. These batteryswitches 134 and 135 connect to various devices 160 of the battery 125and may communicate using different protocols, such as I2C or near-fieldcommunication. In one embodiment, an I2C device of the various devices160 may be a microprocessor embedded in the battery 125 used forwireless charging. In another embodiment, the various devices 160includes a Bluetooth module for reporting battery status to a remotelocation, such as a battery hub. The devices of the various devices 160that the second battery switch 134 and the third battery switch 135connect to are indicated by the data word.

Additionally, the electronic processor 110 may be configured to selectthe second switch 114 and the third switch 115 to connect to respectiveelectrical contacts 155 and 156 based upon the data word to allow theelectrical device 105 to communicate with the various devices 160 of thebattery 125.

Once the first battery switch 133 is connected to either the batterycurrent sensing circuit 145 or the one-wire device 147, the connectionprovides an operating mode voltage back to the electrical device 105 viathe first battery switch 133, the first electrical contact 127, and thefirst switch 113.

The ADC 120 receives the operating mode voltage from the firstelectrical contact 127. The ADC 120 verifies that the received operatingmode voltage matches an operating mode voltage for the specified correctoperating mode indicated by the data word.

FIG. 3 is a flowchart of a method 300 of controlling a battery operatingmode in accordance with some embodiments. In the example illustrated,the method 300 includes connecting the electronic processor 110 to thefirst electrical contact 127 of the battery interface 130 via the firstswitch 113 (block 305). The electronic processor 110 then generates theinitialization pulse (block 310) and transmits the initialization pulseto the signal demultiplexer 140 (block 315).

The method 300 also includes generating, with the signal demultiplexer140, a signal to connect the first battery switch 133 to the pull-upresistor 142 (block 320). By connecting the first battery switch 133 tothe pull-up resistor 142 after the initialization is received, anyincoming data words are not incorrectly sent to any of the one-wiredevice 147 or other various devices 160. The method 300 also includesgenerating, with the electronic processor 110, the data word (block325). The data word is then transmitted by the electronic processor 110to the signal demultiplexer 140, where the data word is received by thewindow comparator circuit 150 (block 330). Based on the data word, thesignal demultiplexer 140 generates a signal to connect the first batteryswitch 133 to one of the battery current sensing circuit 145 and theone-wire device 147 and to the first electrical contact 127 (block 335).

The method 300 also includes receiving, with the ADC 120, an operatingmode voltage that is dependent on what the first battery switch 133and/or other battery switches 134 and 135 are connected to (block 340).The ADC 120 verifies that the correct operating mode voltage has beenreceived (block 345) and that the battery 125 is operating in thecorrect operating mode based on the data word.

Thus, the described invention provides an apparatus for controlling abattery for portable electrical devices. The apparatus helps to managean electrical device's size and cost by reducing the number ofelectrical contacts connecting the device and a removable battery whileproviding full battery monitoring and communication functionality.

In the foregoing specification, specific embodiments have beendescribed. However, one of ordinary skill in the art appreciates thatvarious modifications and changes can be made without departing from thescope of the invention as set forth in the claims below. Accordingly,the specification and figures are to be regarded in an illustrativerather than a restrictive sense, and all such modifications are intendedto be included within the scope of present teachings.

The benefits, advantages, solutions to problems, and any element(s) thatmay cause any benefit, advantage, or solution to occur or become morepronounced are not to be construed as a critical, required, or essentialfeatures or elements of any or all the claims. The invention is definedsolely by the appended claims including any amendments made during thependency of this application and all equivalents of those claims asissued.

Moreover in this document, relational terms such as first and second,top and bottom, and the like may be used solely to distinguish oneentity or action from another entity or action without necessarilyrequiring or implying any actual such relationship or order between suchentities or actions. The terms “comprises,” “comprising,” “has,”“having,” “includes,” “including,” “contains,” “containing” or any othervariation thereof, are intended to cover a non-exclusive inclusion, suchthat a process, method, article, or apparatus that comprises, has,includes, contains a list of elements does not include only thoseelements but may include other elements not expressly listed or inherentto such process, method, article, or apparatus. An element preceded by“comprises . . . a,” “has . . . a,” “includes . . . a,” or “contains . .. a” does not, without more constraints, preclude the existence ofadditional identical elements in the process, method, article, orapparatus that comprises, has, includes, contains the element. The terms“a” and “an” are defined as one or more unless explicitly statedotherwise herein. The terms “substantially,” “essentially,”“approximately,” “about” or any other version thereof, are defined asbeing close to as understood by one of ordinary skill in the art, and inone non-limiting embodiment the term is defined to be within 10%, inanother embodiment within 5%, in another embodiment within 1% and inanother embodiment within 0.5%. The term “coupled” as used herein isdefined as connected, although not necessarily directly and notnecessarily mechanically. A device or structure that is “configured” ina certain way is configured in at least that way, but may also beconfigured in ways that are not listed.

It will be appreciated that some embodiments may be comprised of one ormore generic or specialized processors (or “processing devices”) such asmicroprocessors, digital signal processors, customized processors andfield programmable gate arrays (FPGAs) and unique stored programinstructions (including both software and firmware) that control the oneor more processors to implement, in conjunction with certainnon-processor circuits, some, most, or all of the functions of themethod and/or apparatus described herein. Alternatively, some or allfunctions could be implemented by a state machine that has no storedprogram instructions, or in one or more application specific integratedcircuits (ASICs), in which each function or some combinations of certainof the functions are implemented as custom logic. Of course, acombination of the two approaches could be used.

Moreover, an embodiment can be implemented as a computer-readablestorage medium having computer readable code stored thereon forprogramming a computer (e.g., comprising a processor) to perform amethod as described and claimed herein. Examples of suchcomputer-readable storage mediums include, but are not limited to, ahard disk, a CD-ROM, an optical storage device, a magnetic storagedevice, a ROM (Read Only Memory), a PROM (Programmable Read OnlyMemory), an EPROM (Erasable Programmable Read Only Memory), an EEPROM(Electrically Erasable Programmable Read Only Memory) and a Flashmemory. Further, it is expected that one of ordinary skill,notwithstanding possibly significant effort and many design choicesmotivated by, for example, available time, current technology, andeconomic considerations, when guided by the concepts and principlesdisclosed herein will be readily capable of generating such softwareinstructions and programs and ICs with minimal experimentation.

The Abstract of the Disclosure is provided to allow the reader toquickly ascertain the nature of the technical disclosure. It issubmitted with the understanding that it will not be used to interpretor limit the scope or meaning of the claims. In addition, in theforegoing Detailed Description, it can be seen that various features aregrouped together in various embodiments for the purpose of streamliningthe disclosure. This method of disclosure is not to be interpreted asreflecting an intention that the claimed embodiments require morefeatures than are expressly recited in each claim. Rather, as thefollowing claims reflect, inventive subject matter lies in less than allfeatures of a single disclosed embodiment. Thus, the following claimsare hereby incorporated into the Detailed Description, with each claimstanding on its own as a separately claimed subject matter.

We claim:
 1. An apparatus for controlling a battery operating mode, theapparatus comprising an electrical device, the electrical deviceincluding a plurality of switches, an analog-to-digital converterconfigured to receive an operating mode voltage and an electronicprocessor, the electronic processor configured to generate aninitialization pulse, generate a data word indicating a desiredoperating mode, and verify a correct operating mode based on theoperating mode voltage; a battery interface, the battery interfaceincluding a first electrical contact, a first one of the plurality ofswitches electrically connecting the electronic processor to the firstelectrical contact; and a battery, the battery including a plurality ofbattery switches and a signal demultiplexer electrically connected tothe first electrical contact, the signal demultiplexer configured toreceive the initialization pulse, receive the data word, generate asignal to electrically connect a first battery switch of the pluralityof battery switches to the first electrical contact for transmitting theoperating mode voltage to the analog-to-digital converter of theelectrical device, the first battery switch selected based on the dataword.
 2. The apparatus of claim 1, wherein a pulse width of theinitialization pulse is greater than a pulse width of a reset pulse of acurrent operating mode of the battery.
 3. The apparatus of claim 1,wherein the signal demultiplexer generates a signal to connect the firstbattery switch to a pull-up resistor when the initialization pulse isreceived.
 4. The apparatus of claim 1, the electrical device furthercomprising a pull-down resistor.
 5. The apparatus of claim 4, whereinthe electrical device generates the initialization pulse and the dataword using the first one of the plurality of switches and the pull-downresistor.
 6. The apparatus of claim 1, wherein the electronic processoris further configured to generate a signal to electrically connect asecond one of the plurality of switches to a second electrical contactof the battery interface based on the correct operating mode beingverified.
 7. The apparatus of claim 6, wherein the signal demultiplexeris further configured to generate a signal to electrically connect thesecond one of the plurality of battery switches to the second electricalcontact.
 8. The apparatus of claim 7, wherein the second one of theplurality of battery switches is selected based on the data word.
 9. Theapparatus of claim 1, wherein the battery operating mode is an operatingmode selected from the group consisting of an I2C operating mode, anear-field communication operating mode, a battery cell voltagemonitoring operating mode, and a one-wire operating mode.
 10. Theapparatus of claim 1, wherein the data word is received during aspecified time window after receiving the initialization pulse.
 11. Amethod for controlling a battery operating mode, the method comprising:connecting an electronic processor of an electrical device to a firstelectrical contact of a battery interface via a first one a plurality ofswitches; generating, with the electronic processor of the electricaldevice, an initialization pulse for a signal demultiplexer of a battery;transmitting the initialization pulse to the signal demultiplexer viathe first electrical contact of the battery interface; generating, withthe electronic processor, a data word indicating a desired operatingmode of the battery; transmitting the data word to the signaldemultiplexer via the first electrical contact; generating, with thesignal demultiplexer, a signal to electrically connect a first batteryswitch of a plurality of battery switches to the first electricalcontact, the first battery switch selected based on the data word;receiving, with the signal demultiplexer, a signal indicating anoperating mode voltage from the first battery switch; receiving, with ananalog-to-digital converter of the electrical device, a signalindicating the operating mode voltage to the electronic processor viathe first electrical contact; and verifying, with the electronicprocessor, a correct operating mode based on the operating mode voltage.12. The method of claim 11, wherein a pulse width of the initializationpulse is greater than a pulse width of a reset pulse of a currentoperating mode of the battery.
 13. The method of claim 11, wherein thesignal demultiplexer generates a signal to connect the first batteryswitch to a pull-up resistor when the initialization pulse is received.14. The method of claim 11, wherein the electrical device includes apull-down resistor.
 15. The method of claim 14, wherein the electronicprocessor generates the initialization pulse and the data word using thefirst one of the plurality of switches and the pull-down resistor. 16.The method of claim 11, further comprising generating, with theelectronic processor, a signal to electrically connect a second one ofthe plurality of switches to a second electrical contact of the batteryinterface based on the correct operating mode being verified.
 17. Themethod of claim 16, further comprising generating, with the signaldemultiplexer, a signal to electrically connect a second battery switchof the plurality of battery switches to the second electrical contact.18. The method of claim 17, wherein the second battery switch isselected based on the data word.
 19. The method of claim 11, wherein thebattery operating mode is an operating mode selected from the groupconsisting of an I2C operating mode, a near-field communicationoperating mode, a battery cell voltage monitoring operating mode, and aone-wire operating mode.
 20. The method of claim 11, wherein the dataword is received during a specified time window after receiving theinitialization pulse.